The present invention relates to a winding arrangement for an electrical machine, and also to a method for producing a winding arrangement of this kind for an electrical machine.
It is generally known that a machine component of an electrical machine, such as a stator or a rotor, for example, can be wound using different winding techniques. In the process, slots in the machine component are provided with a winding wire with the aid of winding techniques such as flyer winding, needle winding or coil winding, for example.
Depending on the geometric configuration and arrangement of the slots in the machine component and the winding scheme used, there is a risk of a section or a turn of the winding wire coming loose or slipping from the last-wound coil and escaping from the slot. It is possible for the winding wire to slip or come loose as early as during the winding process during production of the electrical machine, during the course of subsequent manufacturing steps for assembly or during operation of the electrical machine. If that section of the winding wire which has slipped or shifted enters the air gap in the electrical machine, this can lead to a mechanical blockage.
Document DE 198 26 886 discloses a rotor for an electric motor which has an additional wrapping around the connection wires in the region between the commutator and the rotor body. This additional wrapping has the effect that the connection wires have a greater degree of stability, and therefore no fatigue failure can occur during operation, in particular during the so-called vibration tests. However, the wound wires of the rotor or of the armature are not separately secured or fixed by this additional wrapping, and therefore it is still possible for the slipping of the wire described further above to occur.
Document DE 26 20 917 discloses a method and an arrangement for fixing free winding ends of rotor windings by impregnation. In the process, prior to impregnation, one or more absorbent threads or tapes are placed around the free winding ends over the entire circumference and the end pieces of said threads or tapes are passed to so-called trickle stations.
In further embodiments of this document, impregnation resin is applied only to the end pieces of the absorbent threads or tapes. A variant in which the end pieces of the absorbent threads or tapes are inserted into the slots is also known.
Ultimately, all of said variants serve to fix the winding wire against mechanical forces which occur during operation with the aid of additional means, such as the threads or tapes which are provided with impregnation resin, for example.
These additional means increase the material costs and create additional complexity during assembly of the electrical machine.